const COINS: &[u32] = &[100, 50, 30, 20, 10, 5, 2, 1];

pub fn dp_rec_mc(amount: u32) -> u32 {
    COINS.iter().scan(amount, |rem, coin| {
        let count = *rem / coin;
        *rem %= coin;
        Some(count)
    }).sum()
}
